Getting a molecule to do what you want it to do is not always easy. An organic molecule will absorb only certain wavelengths of light based on its arrangement of electrons, which can be difficult to fine tune. Even so, the ability to make substances that respond to only specific ranges of the spectrum could lead to important new applications. Getting a molecule to do what you want it to do is not always easy. An organic molecule will absorb only certain wavelengths of light based on its arrangement of electrons, which can be difficult to fine tune. Even so, the ability to make substances that respond to only specific ranges of the spectrum could lead to important new applications. Materials Science Phys.org – latest science and technology news stories